semantics

Semantics & digital data processing

Beirut, 9-10 March 2015

Establishing a framework for scholarly editing and publishing in the 21st century

Mokhtar BEN HENDA

Semantics: Better computational description of Semantics: Better computational description of sciencescience

Information is given explicit meaning so that machines can process it more intelligently;

Instead of just creating standard terms for concepts as is done in XML, the Semantic Web also allows users to provide formal definitions for the standard terms they create so that machines can use inference algorithms to reason about the terms;

A crucial component to the Semantic Web is the definition and use of ontologies,

Basics of semantic WebBasics of semantic Web XML

XML is a language for transmitting structured information. If the goal of the web is to enable not only communication between people, but also between machines, then XML seems a good basis not only for documents to be read by people, but for data to be read by machines.

RDF RDF(Resource Description Framework) is a directed, labeled graph data

format for representing information in the Web. It is just a data model that does not have any significant semantics. RDF Schema is used to define a vocabulary for use in RDF models. In particular, it allows to define the classes used to type resources and to define the properties that resources can have.

OWL OWL was designed to provide a common way to process the content of web

information instead of displaying it. It is primarily concerned with defining terminology that can be used in RDF documents. Syntactically, an OWL ontology is a valid RDF document and as such also a well-formed XML document.

SPARQL Is a set of specifications that provide languages and protocols to query and

manipulate RDF graph content on the Web or in an RDF store

OntologiesOntologies Principle:

From characters string to word meaning From words listing to words relations From indexes to ontologies

Ontologies

Semantic links

Vocabularies

Data ModelsData Models

bank

fiddleviolin

violistfiddler

string

rec: 12345- financial instituterec: 54321- side of a riverrec: 9876- small string instrumentrec: 65438- musician playing violinrec:42654- musician

rec:25876- string instrument

rec:35576- string of instrumentrec:29551- underwear

type-of

type-of

part-of

Vocabulary of a languageConceptsRelations

1

2

2

1

1

2

© Piek Vossen

Capturing Semantics in XML DocumentsCapturing Semantics in XML Documents

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XML

app#1Semantics: Code to interpret the dataAction: Code to process the data

app#2Semantics: Code to interpret the dataAction: Code to process the data

Meaning (semantics) applied on a per-XML-Meaning (semantics) applied on a per-XML-application basisapplication basis

© Katia Sycara and Massimo Paolucci

OWL (Ontology Web Language)OWL (Ontology Web Language)

XML

app#1Action: Code to process the data

app#2Action: Code to process the data

OWL DocumentSemantic Definitions

Handles separate concept definitions (semantics) from applicationExpress concept definitions using a standard vocabulary


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OWL and logicsOWL and logics OWL relies on Description Logics Logics provide automatic

CheckCheck of consistency of concept definitions CompletionCompletion of concept definitions ClassificationClassification of new instances and concepts ExtractionExtraction of implicit knowledge in the documents

OWL greatly expands the vocabulary for multiple possible constructs

XML Schema provides some of those properties to some extent


RDF (Resource Description Framework)RDF (Resource Description Framework)

Provide basic syntax for OWL Use of URI for uniqueunique identification of

concepts, instances and relations Expression of relations between objects

and concepts (RDF triples)

Problem: no structure© Katia Sycara and Massimo Paolucci

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RDF SchemaRDF Schema Add basic structure to RDF

Class/Subclass declaration Instances Properties (relations) Multiple inheritance

12(24)

NOTES• everything is a replaceable bean• all communication via fixed APIs • low coupling, high modularity, high extensibility

…

HTMLdocs

RTFdocs

XMLdocs

PDFdocs

email

XMLDocumentFormat

HTMLDocumentFormat

PDFDocumentFormat

…DocumentFormatLayer (LRs)

XML Oracle PostgreSql .ser

DataStore Layer

Corpus Document

DocumentContent

AnnotationSet

Annotation FeatureMap

Corpus Layer (LRs)

NOTES (2)• eg: Protégé LR & VR both wrapped in Res. (bean) API

• ontology repositories and inference are the same: KAON + Sesame + Orenge + ?

GATE APIs

Processing Layer (PRs)

NE Co-ref TEs TRs POS …

Onto-logy

ProtégéOnto-logy

Word-net

Gaz-etteers

Language Resource Layer (LRs)

...

Application Layer

ANNIE OBIE …IDE GUI Layer (VRs)

ADiff OntolVR DocVR ... WebServices

Sheffield Natural Language Processing GroupSheffield Natural Language Processing Group

Semantic Web: cartographic searchingSemantic Web: cartographic searching

Semantic Web: cartographic searchingSemantic Web: cartographic searching Conceptual charts

Reproduce semantic links like charts One concept can have numerous semantic

links

http://www.touchgraph.com/TGGoogleBrowser.html


http://www.oskope.com


• http://vionto.com/show/


Topic Maps : http://highwire.stanford.edu/lists/artbytopic.dtl

SKOS: Simple Knowledge Org. SystemsSKOS: Simple Knowledge Org. Systems SKOS: specifications

and standards to support within the framework of the Semantic Web, the use of knowledge organization systems (KOS) such as: thesauri, classification schemes, subject heading lists Taxonomies

http://www.ebusiness-unibw.org/tools/skos2owl/

SKOS PlaySKOS Play SKOS Play thesaurus is a

visualization service of SKOS formatted taxonomies or vocabularies.

More generally, it is used to view or print a knowledge organization system expressed in SKOS.

http://labs.sparna.fr/skos-play/upload?lang=en

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